Of the total thermal energy supplied to a heat engine, only a small part is efficiently utilized, while a major part is lost in exhaust gases and in the machine cooling fluid. The device of the invention enables conversion of this waste thermal energy into the mechanical energy which is transmitted to the heat engine shaft through a transmission type unit. In that way the engine efficiency can be considerably increased, that is the specific fuel consumption of a heat engine can be decreased.
Of the total thermal energy losses of the driving engines, the major part is lost through exhaust gas discharged into the environment. For that reason great effort is expended in order to utilize the exhaust gas energy.
In case of piston-type internal combustion engines, for a long time the exhaust gases energy has been utilized for turbocharging (gas expansion in a blade-type turbine driving a compressor for forced supply of air or an air and fuel mixture). That is a well-known engine forcing by means of which the engine power is considerably increased and the efficiency increased only insignificantly. In the case of propulsion engines, the interaction of a turbine and a compressor is regularly used in the operating cycle.
Recently there has been an intensive develoment of the blade-type turbine where the exhaust gas energy is converted into mechanical energy which is transmitted to the engine shaft (of the known investigations of the Cummins Company, USA etc.). In this way engine efficiency has been modestly increased so far. Apart from other deficiencies of the turbines, the unsolved problem is the regulation of the turbine at a variable gas flow with partial duty of the internal combustion engine. With steam piston engines, steam and gas turbines and similar engines, the subsequent expansion of exhaust gas for generation of additional mechanical energy on the engine shaft has not been used up to now.